§1.1 Field of the Invention
The present invention concerns advertising. In particular, the present invention concerns determining a minimum price to be charged for serving an online advertisement.
§1.2 Related Art
Advertising using traditional media, such as television, radio, newspapers and magazines, is well known. Unfortunately, even when armed with demographic studies and entirely reasonable assumptions about the typical audience of various media outlets, advertisers recognize that much of their ad budget is simply wasted. Moreover, it is very difficult to identify and eliminate such waste.
Recently, advertising over more interactive media has become popular. For example, as the number of people using the Internet has exploded, advertisers have come to appreciate media and services offered over the Internet as a potentially powerful way to advertise.
Advertisers have developed several strategies in an attempt to maximize the value of such advertising. In one strategy, advertisers use popular presences or means for providing interactive media or services (referred to as “Web sites” in the specification without loss of generality) as conduits to reach a large audience. Using this first approach, an advertiser may place ads on the home page of the New York Times Web site, or the USA Today Web site, for example. In another strategy, an advertiser may attempt to target its ads to more narrow niche audiences, thereby increasing the likelihood of a positive response by the audience. For example, an agency promoting tourism in the Costa Rican rainforest might place ads on the ecotourism-travel subdirectory of the Yahoo Web site.
Regardless of the strategy, Web site-based ads (also referred to as “Web ads”) are typically presented to their advertising audience in the form “banner ads”—i.e., a rectangular box that includes graphic components. When a member of the advertising audience (referred to as a “viewer” or “user” in the Specification without loss of generality) selects one of these banner ads by clicking on it, embedded hypertext links typically direct the viewer to the advertiser's Web site. This process, wherein the viewer selects an ad, is commonly referred to as a “click-through” (“Click-through” is intended to cover any user selection.). The ratio of the number of click-throughs to the number of impressions of the ad (i.e., the number of times an ad is displayed) is commonly referred to as the “click-through rate” of the ad. A “conversion” is said to occur when a user consummates a transaction related to a previously served ad. What constitutes a conversion may vary from case to case and can be determined in a variety of ways. For example, it may be the case that a conversion occurs when a user clicks on an ad, is referred to the advertiser's web page, and consummates a purchase there before leaving that web page. Alternatively, a conversion may be defined as a user being shown an ad, and making a purchase on the advertiser's web page within a predetermined time (e.g., seven days). Many other definitions of what constitutes a conversion are possible. The ratio of the number of conversions to the number of impressions of the ad (i.e., the number of times an ad is displayed) is commonly referred to as the conversion rate. If a conversion is defined to be able to occur within a predetermined time since the serving of an ad, one possible definition of the conversion rate might only consider ads that have been served more than the predetermined time in the past.
Despite the initial promise of Web site-based advertisement, there remain several problems with existing approaches. Although advertisers are able to reach a large audience, they are frequently dissatisfied with the return on their advertisement investment. Some have attempted to improve ad performance by tracking the online habits of users, but this approach has led to privacy concerns.
Similarly, the hosts of Web sites on which the ads are presented (referred to as “Web site hosts” or “ad consumers”) have the challenge of maximizing ad revenue without impairing their users' experience. Some Web site hosts have chosen to place advertising revenues over the interests of users. One such Web site is “Overture.com”, which hosts a so-called “search engine” service returning advertisements masquerading as “search results” in response to user queries. The Overture.com web site permits advertisers to pay to position an ad for their Web site (or a target Web site) higher up on the list of purported search results. If such schemes where the advertiser only pays if a user clicks on the ad (i.e., cost-per-click) are implemented, the advertiser lacks incentive to target their ads effectively, since a poorly targeted ad will not be clicked and therefore will not require payment. Consequently, high cost-per-click ads show up near or at the top, but do not necessarily translate into real revenue for the ad publisher because viewers don't click on them. Furthermore, ads that viewers would click on are further down the list, or not on the list at all, and so relevancy of ads is compromised.
Some online advertising systems permit advertisers to target the serving of their ads. Such systems may do so by allowing advertisers to place one or more serving constraints on an ad. One of the most popular serving constraints is setting one or more keywords such that an ad will only be served if at least some of the keywords “match” a search query, in an advertising system that serves ads with search results. Other serving constraints are possible.
Often, different advertisers want to reach the same target audience, and therefore would like their ads to be served subject to the same serving constraints. Accordingly, serving constraints can be thought of as targeting criteria. If there is a limited number of spots (also referred to as “inventory”) for the competing ads, competition of competing ads from competing advertisers should be arbitrated. Similarly, competition for relative presentation attributes of ads, such as spatial or temporal positioning, size, etc., should also be arbitrated. Auctions are one way of arbitrating such competitions, such as competitions for keywords, competitions for relative placement, etc. In an advertising system where the serving of ads is subject to an auction, setting a minimum price for each auction can increase revenue, compared to an auction where no minimum prices are set. Conventional systems have used fixed minimum prices for all of their advertising inventory. However, different auctions can sell inventory with different underlying values. Thus, better ways of setting minimum prices are needed.